[#benchmarks]
:idprefix: benchmarks_

= 基准测试

== boost::unordered_[multi]set

所有基准测试均使用 `unordered++_++set++<++unsigned int++>++`(非重复元素） 和 `unordered++_++multiset++<++unsigned int++>++` （重复元素）创建。源代码可 https://github.com/boostorg/boost_unordered_benchmarks/tree/boost_unordered_set[在此处获取] 。

插入基准测试会插入 `n` 个随机值，其中 `n` 的范围在10,000至300万之间。在重复值测试场景中，同一组随机值会平均重复插入 5 次。

在擦除基准测试中，随机删除所有 `n` 个元素直至容器为空。通过键擦除操作使用 `erase(const key++_++type&)` 方法，每次调用将移除整个等效元素组。

成功查找基准测试通过按照元素的原始插入顺序查找全部 `n` 个值来完成。

未命中查找基准测试使用不同种子值生成的 `n` 个随机整数进行。

=== GCC 12 + libstdc++-v3, x64

==== 插入

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/running insertion.xlsx.practice.png[width=250,link=_images/benchmarks-set/gcc/running insertion.xlsx.practice.png,window=_blank]
|image::benchmarks-set/gcc/running insertion.xlsx.practice non-unique.png[width=250,link=_images/benchmarks-set/gcc/running insertion.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/gcc/running insertion.xlsx.practice non-unique 5.png[width=250,link=_images/benchmarks-set/gcc/running insertion.xlsx.practice non-unique 5.png,window=_blank]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5 |===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/running insertion.xlsx.practice norehash.png[width=250,link=_images/benchmarks-set/gcc/running insertion.xlsx.practice norehash.png,window=_blank]
|image::benchmarks-set/gcc/running insertion.xlsx.practice norehash non-unique.png[width=250,link=_images/benchmarks-set/gcc/running insertion.xlsx.practice norehash non-unique.png,window=_blank]
|image::benchmarks-set/gcc/running insertion.xlsx.practice norehash non-unique 5.png[width=250,link=_images/benchmarks-set/gcc/running insertion.xlsx.practice norehash non-unique 5.png,window=_blank]

h|非重复元素, + 预先 `reserve` h|重复元素, + 预先 `reserve` h|重复元素, + 最大负载因子 5, + 预先 `reserve`

|===

==== 擦除

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/scattered erasure.xlsx.practice.png[width=250,link=_images/benchmarks-set/gcc/scattered erasure.xlsx.practice.png,window=_blank]
|image::benchmarks-set/gcc/scattered erasure.xlsx.practice non-unique.png[width=250,link=_images/benchmarks-set/gcc/scattered erasure.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/gcc/scattered erasure.xlsx.practice non-unique 5.png[width=250,link=_images/benchmarks-set/gcc/scattered erasure.xlsx.practice non-unique 5.png,window=_blank]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|
|image::benchmarks-set/gcc/scattered erasure by key.xlsx.practice non-unique.png[width=250,link=_images/benchmarks-set/gcc/scattered erasure by key.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/gcc/scattered erasure by key.xlsx.practice non-unique 5.png[width=250,link=_images/benchmarks-set/gcc/scattered erasure by key.xlsx.practice non-unique 5.png,window=_blank]

|
h|通过键操作， 重复元素 h|通过键操作, 重复元素, + 最大负载因子 5

|===

==== 成功查找

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/scattered successful looukp.xlsx.practice.png[width=250,window=_blank,link=_images/benchmarks-set/gcc/scattered successful looukp.xlsx.practice.png]
|image::benchmarks-set/gcc/scattered successful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/gcc/scattered successful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/gcc/scattered successful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/gcc/scattered successful looukp.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|===

==== 未命中查找

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice.png[width=250,window=_blank,link=_images/benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice.png]
|image::benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/gcc/scattered unsuccessful looukp.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|===

=== Clang 15 + libc++, x64

==== 插入

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice.png[width=250, window=_blank,link=_images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice.png]
|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice non-unique.png[width=250, window=_blank,link=_images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice non-unique.png]
|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice non-unique 5.png[width=250, window=_blank,link=_images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash.png]
|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash non-unique.png]
|image::benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/running insertion.xlsx.practice norehash non-unique 5.png]

h|非重复元素, + 预先 `reserve` h|重复元素, + 预先 `reserve` h|重复元素, + 最大负载因子 5, + 预先 `reserve`

|===

==== 擦除

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice.png]
|image::benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice non-unique.png]
|image::benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/scattered erasure.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|
|image::benchmarks-set/clang_libcpp/scattered erasure by key.xlsx.practice non-unique.png[width=250,link=_images/benchmarks-set/clang_libcpp/scattered erasure by key.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/clang_libcpp/scattered erasure by key.xlsx.practice non-unique 5.png[width=250,link=_images/benchmarks-set/clang_libcpp/scattered erasure by key.xlsx.practice non-unique 5.png,window=_blank]

|
h|通过键操作， 重复元素 h|通过键操作, 重复元素, + 最大负载因子 5

|===

==== 成功查找

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice.png]
|image::benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/scattered successful looukp.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|===

==== 未命中查找

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice.png]
|image::benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/clang_libcpp/scattered unsuccessful looukp.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|===

=== Visual Studio 2022 + Dinkumware, x64

==== 插入

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/running insertion.xlsx.practice.png[width=250,window=_blank,link=_images/benchmarks-set/vs/running insertion.xlsx.practice.png]
|image::benchmarks-set/vs/running insertion.xlsx.practice non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/vs/running insertion.xlsx.practice non-unique.png]
|image::benchmarks-set/vs/running insertion.xlsx.practice non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/vs/running insertion.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/running insertion.xlsx.practice norehash.png[width=250,window=_blank,link=_images/benchmarks-set/vs/running insertion.xlsx.practice norehash.png]
|image::benchmarks-set/vs/running insertion.xlsx.practice norehash non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/vs/running insertion.xlsx.practice norehash non-unique.png]
|image::benchmarks-set/vs/running insertion.xlsx.practice norehash non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/vs/running insertion.xlsx.practice norehash non-unique 5.png]

h|非重复元素, + 预先 `reserve` h|重复元素, + 预先 `reserve` h|重复元素, + 最大负载因子 5, + 预先 `reserve`

|===

==== 擦除

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/scattered erasure.xlsx.practice.png[width=250,window=_blank,link=_images/benchmarks-set/vs/scattered erasure.xlsx.practice.png]
|image::benchmarks-set/vs/scattered erasure.xlsx.practice non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/vs/scattered erasure.xlsx.practice non-unique.png]
|image::benchmarks-set/vs/scattered erasure.xlsx.practice non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/vs/scattered erasure.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|
|image::benchmarks-set/vs/scattered erasure by key.xlsx.practice non-unique.png[width=250,link=_images/benchmarks-set/vs/scattered erasure by key.xlsx.practice non-unique.png,window=_blank]
|image::benchmarks-set/vs/scattered erasure by key.xlsx.practice non-unique 5.png[width=250,link=_images/benchmarks-set/vs/scattered erasure by key.xlsx.practice non-unique 5.png,window=_blank]

|
h|通过键操作， 重复元素 h|通过键操作, 重复元素, + 最大负载因子 5

|===

==== 成功查找

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/scattered successful looukp.xlsx.practice.png[width=250,window=_blank,link=_images/benchmarks-set/vs/scattered successful looukp.xlsx.practice.png]
|image::benchmarks-set/vs/scattered successful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/vs/scattered successful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/vs/scattered successful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/vs/scattered successful looukp.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|===

==== 未命中查找

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice.png[width=250,window=_blank,link=_images/benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice.png]
|image::benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice non-unique.png[width=250,window=_blank,link=_images/benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice non-unique.png]
|image::benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice non-unique 5.png[width=250,window=_blank,link=_images/benchmarks-set/vs/scattered unsuccessful looukp.xlsx.practice non-unique 5.png]

h|非重复元素 h|重复元素 h|重复元素, + 最大负载因子 5

|===

== boost::unordered_(flat|node)_map

所有基准测试均为使用以下链接来创建的：

* https://abseil.io/docs/cpp/guides/container[`absl::flat++_++hash++_++map`^]`++<++uint64++_++t, uint64++_++t++>++`
* `boost::unordered_map<uint64_t, uint64_t="">`</uint64_t,>
* `boost::unordered_flat_map<uint64_t, uint64_t="">`</uint64_t,>
* `boost::unordered_node_map<uint64_t, uint64_t="">`</uint64_t,>

源代码可 https://github.com/boostorg/boost_unordered_benchmarks/tree/boost_unordered_flat_map[在此处获取] 。

插入基准测试的操作将插入 `n` 个随机值，其中 `n` 的范围在10,000至1000万之间。

擦除基准测试会遍历全部 `n` 个元素，并删除其中键值为奇数的元素（平均约占50%）。

成功查找基准测试通过按照元素的原始插入顺序查找全部 `n` 个值来完成。

未命中查找基准测试使用不同种子值生成的 `n` 个随机整数进行。


=== GCC 12, x64


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/gcc-x64/Running insertion.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/gcc-x64/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x64/Running erasure.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/gcc-x64/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x64/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/gcc-x64/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x64/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/gcc-x64/Scattered unsuccessful looukp.xlsx.plot.png]

h|插入的执行 h|擦除的执行 h|成功查找 h|未命中查找

|===

=== Clang 15, x64


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/clang-x64/Running insertion.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-x64/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x64/Running erasure.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-x64/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x64/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-x64/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x64/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-x64/Scattered unsuccessful looukp.xlsx.plot.png]

h|插入的执行 h|擦除的执行 h|成功查找 h|未命中查找

|===

=== Visual Studio 2022, x64


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/vs-x64/Running insertion.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/vs-x64/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x64/Running erasure.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/vs-x64/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x64/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/vs-x64/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x64/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/vs-x64/Scattered unsuccessful looukp.xlsx.plot.png]

h|插入的执行 h|擦除的执行 h|成功查找 h|未命中查找

|===

=== Clang 12, ARM64


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/clang-arm64/Running insertion.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-arm64/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/clang-arm64/Running erasure.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-arm64/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/clang-arm64/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-arm64/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/clang-arm64/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-arm64/Scattered unsuccessful looukp.xlsx.plot.png]

h|插入的执行 h|擦除的执行 h|成功查找 h|未命中查找

|===

=== GCC 12, x86


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/gcc-x86/Running insertion.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/gcc-x86/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x86/Running erasure.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/gcc-x86/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x86/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/gcc-x86/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/gcc-x86/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/gcc-x86/Scattered unsuccessful looukp.xlsx.plot.png]

h|插入的执行 h|擦除的执行 h|成功查找 h|未命中查找

|===

=== Clang 15, x86


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/clang-x86/Running insertion.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-x86/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x86/Running erasure.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-x86/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x86/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-x86/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/clang-x86/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/clang-x86/Scattered unsuccessful looukp.xlsx.plot.png]

h|插入的执行 h|擦除的执行 h|成功查找 h|未命中查找

|===

=== Visual Studio 2022, x86


[caption=]
[cols="4*^.^a", frame=all, grid=all]
|===

|image::benchmarks-flat_map/vs-x86/Running insertion.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/vs-x86/Running insertion.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x86/Running erasure.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/vs-x86/Running erasure.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x86/Scattered successful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/vs-x86/Scattered successful looukp.xlsx.plot.png]
|image::benchmarks-flat_map/vs-x86/Scattered unsuccessful looukp.xlsx.plot.png[width=250,window=_blank,link=_images/benchmarks-flat_map/vs-x86/Scattered unsuccessful looukp.xlsx.plot.png]

h|插入的执行 h|擦除的执行 h|成功查找 h|未命中查找

|===

== boost::concurrent_(flat|node)_map

所有基准测试均为使用以下链接来创建的：

* `https://spec.oneapi.io/versions/latest/elements/oneTBB/source/containers/concurrent_hash_map_cls.html[oneapi::tbb::concurrent_hash_map^]<int, int="">`</int,>
* `https://github.com/greg7mdp/gtl/blob/main/docs/phmap.md[gtl::parallel_flat_hash_map^]<int, int="">` （含64个子映射）</int,>
* `boost::concurrent_flat_map<int, int="">`</int,>
* `boost::concurrent_node_map<int, int="">`</int,>

源代码可 https://github.com/boostorg/boost_unordered_benchmarks/tree/boost_concurrent_flat_map[在此处获取] 。

基准测试使用__T__个线程（数量1至16之间）并发执行随机选择的操作，这些操作包括**更新**、**成功查找**和**未命中查找**三种类型。操作使用的键遵循 https://en.wikipedia.org/wiki/Zipf%27s_law#Formal_definition[齐夫分布] ，并采用不同的__偏斜__参数：偏斜值越高，键的分布越集中在取值区间的较低数值区域。

`boost::concurrent_flat_map` 和 `boost::concurrent_node_map` 分别通过常规访问和 xref:concurrent.adoc#concurrent_bulk_visitation[批量访问] 进行演练：在批量访问的情况下，查找键会缓存在本地数组中，每当缓冲区大小达到 `xref:reference/concurrent_flat_map.adoc#concurrent_flat_map_constants[bulk_visit_size]` 时，再一次性处理这些键。

=== GCC 12, x64


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.01.png"]
|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.5.png"]
|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.500k, 0.99.png"]

h|50万次更新, 450万次查找 + 偏斜=0.01 h|50万次更新, 450万次查找 + 偏斜=0.5 h|50万次更新, 450万次查找 + 偏斜=0.99 |===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.01.png"]
|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.5.png"]
|image::benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x64/Parallel workload.xlsx.5M, 0.99.png"]

h|500万次更新, 4500万次查找 + 偏斜=0.01 h|500万次更新, 4500万次查找 + 偏斜=0.5 h|500万次更新, 4500万次查找 + 偏斜=0.99 |===

=== Clang 15, x64


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.01.png"]
|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.5.png"]
|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.500k, 0.99.png"]

h|50万次更新, 450万次查找 + 偏斜=0.01 h|50万次更新, 450万次查找 + 偏斜=0.5 h|50万次更新, 450万次查找 + 偏斜=0.99 |===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.01.png"]
|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.5.png"]
|image::benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x64/Parallel workload.xlsx.5M, 0.99.png"]

h|500万次更新, 4500万次查找 + 偏斜=0.01 h|500万次更新, 4500万次查找 + 偏斜=0.5 h|500万次更新, 4500万次查找 + 偏斜=0.99 |===

=== Visual Studio 2022, x64


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.01.png"]
|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.5.png"]
|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.500k, 0.99.png"]

h|50万次更新, 450万次查找 + 偏斜=0.01 h|50万次更新, 450万次查找 + 偏斜=0.5 h|50万次更新, 450万次查找 + 偏斜=0.99 |===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.01.png"]
|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.5.png"]
|image::benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x64/Parallel workload.xlsx.5M, 0.99.png"]

h|500万次更新, 4500万次查找 + 偏斜=0.01 h|500万次更新, 4500万次查找 + 偏斜=0.5 h|500万次更新, 4500万次查找 + 偏斜=0.99 |===

=== Clang 12, ARM64


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.01.png"]
|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.5.png"]
|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.500k, 0.99.png"]

h|50万次更新, 450万次查找 + 偏斜=0.01 h|50万次更新, 450万次查找 + 偏斜=0.5 h|50万次更新, 450万次查找 + 偏斜=0.99 |===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.01.png"]
|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.5.png"]
|image::benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-arm64/Parallel workload.xlsx.5M, 0.99.png"]

h|500万次更新, 4500万次查找 + 偏斜=0.01 h|500万次更新, 4500万次查找 + 偏斜=0.5 h|500万次更新, 4500万次查找 + 偏斜=0.99 |===

=== GCC 12, x86


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.01.png"]
|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.5.png"]
|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.500k, 0.99.png"]

h|50万次更新, 450万次查找 + 偏斜=0.01 h|50万次更新, 450万次查找 + 偏斜=0.5 h|50万次更新, 450万次查找 + 偏斜=0.99 |===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.01.png"]
|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.5.png"]
|image::benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/gcc-x86/Parallel workload.xlsx.5M, 0.99.png"]

h|500万次更新, 4500万次查找 + 偏斜=0.01 h|500万次更新, 4500万次查找 + 偏斜=0.5 h|500万次更新, 4500万次查找 + 偏斜=0.99 |===

=== Clang 15, x86


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.01.png"]
|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.5.png"]
|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.500k, 0.99.png"]

h|50万次更新, 450万次查找 + 偏斜=0.01 h|50万次更新, 450万次查找 + 偏斜=0.5 h|50万次更新, 450万次查找 + 偏斜=0.99 |===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.01.png"]
|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.5.png"]
|image::benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/clang-x86/Parallel workload.xlsx.5M, 0.99.png"]

h|500万次更新, 4500万次查找 + 偏斜=0.01 h|500万次更新, 4500万次查找 + 偏斜=0.5 h|500万次更新, 4500万次查找 + 偏斜=0.99 |===

=== Visual Studio 2022, x86


[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.01.png"]
|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.5.png"]
|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.500k, 0.99.png"]

h|50万次更新, 450万次查找 + 偏斜=0.01 h|50万次更新, 450万次查找 + 偏斜=0.5 h|50万次更新, 450万次查找 + 偏斜=0.99 |===

[caption=]
[cols="3*^.^a", frame=all, grid=all]
|===

|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.01.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.01.png"]
|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.5.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.5.png"]
|image::benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.99.png[width=250,window=_blank,link="_images/benchmarks-concurrent_map/vs-x86/Parallel workload.xlsx.5M, 0.99.png"]

h|500万次更新, 4500万次查找 + 偏斜=0.01 h|500万次更新, 4500万次查找 + 偏斜=0.5 h|500万次更新, 4500万次查找 + 偏斜=0.99 |===